Sweating: Its Rapid Response to Muscular Work

Abstract

been purified approximately 300 fold by absorption and elution from diethylaminoethyl (DEAE) cellulose (12) followed by precipitation with 55-percent saturation of ammonium sulfate at 0?C. Moreover, when DEAE cel? lulose is developed with a linear NaCl gradient, the corresponding variant and normal LDH isozymes are eluted at similar points. The mobility of normal and variant LDH isozymes from crude hemolyzates is identical in the sys? tem (75) of varying starch-gel porosity. Such behavior suggests that the molecular weight of normal and variant isozymes is grossly similar (14). The enzymic activity of variant LDH from crude hemolyzate approximates that ob? served in normal American and Nigerian Negroes. The only blood relative available for testing, a paternal uncle, has a normal LDH pattern. Whatever the origin of the observed LDH variation, it is uncommon (75) since no variant LDH patterns were observed among hemo? lyzates obtained from approximately 50 white subjects, 300 American Negroes, 100 Papuans (16), and 200 Nigerians. Fritz and Jacobson (17) examined mouse tissue extracts and observed five LDH-5 components, four LDH-4 com? ponents, three LDH-3 components, two LDH-2 components, and one LDH-1 component in gels prepared with 0.005M /?-mercaptoethanol. These au? thors suggest that this concentration of /?-mercaptoethanol removes bound NAD from a portion of A subunits but not from B subunits. These ob? servations provide a pattern exactly opposite to that in the Nigerian LDH variant. Moreover, the human variant LDH pattern is unaltered in gels con? taining /3-mercaptoethanol in amounts ranging from 0.005 to 0.1M. The vari? ant LDH pattern is also unaltered by electrophoresis under conditions where the gel and cathodic chamber contain 10~3M NAD. Accordingly, we do not believe that the variant pattern is pro? duced by the mechanism of differential binding of NAD. The variant electrophoretic pattern can be most easily interpreted as reflect? ing a mutant allele at the genetic locus producing the LDH B subunit. The observed physical and enzymatic similarities between normal and variant LDH-1, that is, B subunit tetramers, support this interpretation. If the mu? tant product is designated /?, and the normal product B, then a heterozygote at this locus should exhibit the combi? nations shown in the third column of As work continues the sweating rate may then be controlled by thermal factors, such as increased core or hypothalamic temperatures. In cooler environments the same nervous stimuli may be present, but inefTective because of inhibition by the cooler temperature (77).

Modulation of the thermoregulatory sweating response to mild hyperthermia during activation of the muscle metaboreflex in humans

“…Mean skin temperature ( -Tsk) was calculated according to the method of Hardy & Dubois (1938). The SR on the three body sites was measured continuously by the ventilated capsule method (Van Beaumont & Bullard, 1963;Nadel et al 1971;Ogawa, 1975;Yamazaki et al 1994;Kondo et al 1998). Dry nitrogen gas was supplied to three capsules (chest and forearm: 7·06 cmÂ; palm: 1·53 cmÂ) at a rate of 1·5 l min¢ and the humidity of the nitrogen gas flowing out of the capsules was measured using a capacitance hygrometer (HMP 133Y; Vaisala, Finland).…”

H eat storage in upper and lower body during high-intensity exercise in athletes with spinal cord injuries

“…It has been demonstrated that at rest SCI athletes have warmer skin temperature, which enables an earlier onset of sweating, and therefore earlier skin cooling when compared with AB athletes. 16 This upper-body adaptation to an impaired thermoregulatory ability might help compensate for the lower body inability to dissipate stored heat.…”

Effects of exercise intensity, posture, pressure on the back and ambient temperature on palmar sweating responses due to handgrip exercises in humans

“…In the palmar skin, it is well known that the sweating rate can increase without changes in the internal temperature [Kondo et al, , 1999Van Beaumont & Bullard, 1963, 1966. The changes in the sweating rate may be due to non-thermal factors involving activation of mechanosensitive or metabosensitive receptors in exercising muscles Van Beaumont & Bullard, 1963] or emotional or mental stimulation [Kuno, 1956].…”